Stent graft apparatus and method

ABSTRACT

An apparatus and associated surgical method for repairing abdominal aortic aneurysms is disclosed. The apparatus includes first and second stent grafts made from a metal form structure in combination with a flexible fabric, and a flexible guidewire detachably attached to the first stent graft. The first stent graft has an upper tubular body which defines an inlet, and a lower bifurcation which includes a first tubular leg defining a first outlet, and a second tubular leg defining a second outlet. The method includes advancing the first stent graft through one iliac artery and deploying it in the aorta, advancing a guidewire engagement device distally through the other iliac artery and pulling the flexible guidewire into the other iliac artery, advancing a guide catheter over the flexible guidewire into the second tubular leg of the first stent graft, replacing the flexible guide wire with a stiffer guide wire through the guide catheter, and advancing a catheter delivery system provided with a second stent graft over the stiffer guide wire into the second tubular leg of the first stent graft.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. Ser. No. 12/629,436, filed Dec.2, 2009, which is hereby incorporated by reference herein in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to implant devices and methods used inthe abdominal aorta. More particularly, this invention relates to repairdevices and methods for treating abdominal aortic aneurysms.

2. State of the Art

When a blood vessel such as a vein or an artery deteriorates and/orsuffers trauma, such deterioration and/or trauma may impair the bloodvessel's ability to carry blood, and often creates a high risk ofrupture due to the weakened blood vessel's inability to withstandinternal pressures caused by blood flow and normal flexing andcompression of the blood vessel. Impaired blood flow and/or a high riskof rupture may be life threatening to a patient, particularly when theweakened blood vessel is an important (e.g. large) vein or artery. Forexample, the main artery in a human body is the aorta, which suppliesblood to all of the body's organs except the lungs. The aorta isgenerally described with reference to three different portions—theascending aorta, which rises upward from the left ventricle of theheart, the aortic arch, which arches downward from the ascending aorta,and the descending aorta, which extends downward from the aortic archthrough the thorax and the abdomen. The descending aorta divides intotwo iliac arteries which supply blood to the pelvis and lowerextremities. Deterioration or trauma to the aorta may cause abnormaldilation of the wall of the aorta as it passes through the abdomen, acondition which is called an abdominal aortic aneurysm. This type ofaneurysm ordinarily occurs in the portion of the aorta below thekidneys, and if left untreated, will eventually cause the wall of theaorta to rupture. Once the aorta ruptures, fatal hemorrhaging can occurvery quickly. Repair of abdominal aortic aneurysms has typicallyrequired major abdominal surgery in which the diseased segment of theaorta is removed and replaced with a prosthetic device, such as asynthetic stent graft.

To repair the abdominal aortic aneurysm, the synthetic stent graft isdelivered from the femoral or iliac artery to the aneurysm via adelivery catheter. The stent graft is then expanded to secure the stentgraft within the aorta, and to define a passageway through theabnormally dilated section of the aorta to fluidly couple a healthysection of the aorta upstream of the aneurysm with one or more bloodvessels downstream of the aneurysm. For example, if the abdominal aorticaneurysm occurs below the kidney area, then the surgeon generally mustfluidly couple a portion of the aorta upstream of the aneurysm withportions of both of the iliac arteries downstream of the aneurysm tomaintain bloodflow therebetween while excluding the abnormally dilatedsection of the aorta. The risks associated with repairing an abdominalaortic aneurysm are numerous, and the success of such procedures isdependent upon many variables, including the time required to completethe procedure, the type and quality of the stent grafts used, and theability of the surgeon to accurately position the stent grafts in thepatient.

SUMMARY OF THE INVENTION

The present invention is directed to an apparatus and method forrepairing an aneurysm in the abdominal aorta of a patient. The apparatusincludes first and second stent grafts which are attachable to eachother, and a flexible guidewire detachably attached to the first stentgraft.

The first stent graft is preferably made from a metal form structure incombination with a flexible fabric, and has an upper tubular body and alower bifurcation. The upper tubular body defines an inlet, and thelower bifurcation includes a first tubular leg which defines a firstoutlet and a second tubular leg which defines a second outlet. Thesecond tubular leg is shorter than the first tubular leg, and the firstand second tubular legs are in fluid communication with the inlet of theupper tubular body. As discussed below, the guidewire is detachablyattached at one end to the first stent graft at a location upstream ofthe lower bifurcation, and extends through the second tubular leg of thelower bifurcation.

The first stent graft is sufficiently collapsible and flexible to allowit to be inserted into a delivery catheter in a collapsed state fordelivery to a location at and adjacent the aneurysm, and is expandableinto an expanded configuration within the aorta and within a first ofthe two iliac arteries of the patient.

The second stent graft is also preferably made from a metal formstructure in combination with a flexible fabric, and comprises a hollowelongated member which is sufficiently collapsible and flexible to allowit to be inserted into a catheter in a collapsed state for deliverythrough a second of the two iliac arteries, and for partial insertioninto the second tubular leg of the first stent graft in the aortadownstream of the aneurysm. The second stent graft is expandable into anexpanded configuration within the second tubular leg of the first stentgraft and within the second iliac artery. The first and second stentgrafts thus function in the patient to define passageways for bloodflowfrom a healthy section of the aorta upstream of the aneurysm to thecommon iliac arteries downstream of the aneurysm while excluding thedamaged or otherwise unhealthy portion of the aorta as further discussedbelow.

As indicated above, the flexible guidewire is detachably attached to thefirst stent graft at a location upstream of the lower bifurcation (e.g.,to an inner surface of the upper tubular body), and extends through thesecond tubular leg of the lower bifurcation. The guidewire is preferably0.35 mm or less in diameter and at least 65 cm in length. In oneembodiment, the guidewire includes a hook which permits detachableattachment to the upper tubular body of the first stent graft. Inanother embodiment, the upper tubular body of the first stent graftincludes a lip, and the guidewire is detachably attached to the lip. Inyet another embodiment, the guidewire is bonded at its distal end to theupper tubular body of the first stent graft. As further discussed below,the flexible guidewire is manipulatable by a surgeon from the firstiliac artery to the second iliac artery, and functions as a guide for aguide catheter which is advanced over the flexible guidewire and intothe second tubular leg of the first stent graft. The guide catheter isused to detach the flexible guide wire from the second tubular leg ofthe first stent graft, to guide removal of the flexible guide wire, andto guide a stiffer guide wire which is distally advanced into the secondtubular leg of the first stent graft. The guide catheter is then removedand a second catheter delivery system is advanced over the stiffer guidewire through the second iliac artery and into the second tubular leg ofthe first stent graft within the aorta to facilitate delivery anddeployment of the second stent graft therein.

Prior to introducing the first and second stent grafts and flexibleguidewire into the patient, preparations for taking an angiogram of theaneurysm and the surrounding blood vessels are as follows. Incisions aremade in the patient to expose and isolate both femoral arteries. Aneedle having a bore is inserted through one of the incisions into afirst of the two femoral arteries. A thin guidewire is inserted throughthe incision via the bore of the needle into the first of the twofemoral arteries and advanced through the first femoral artery, throughthe first iliac artery (which is a direct continuation of the firstfemoral artery), through a portion of the aorta, to a location in theapproximate vicinity of the aneurysm in the aortic wall. A sheath isthen connected at the site of arteriotomy in the first femoral arteryand an angiogram catheter is inserted through the sheath and advancedinto the abdominal aorta.

An angiogram is performed and measurements are taken to determine thedistance from the aneurysm to the bifurcation (e.g., the location wherethe aorta branches into the two common iliac arteries).

After the angiogram is performed, the thin guide wire is replaced with astiffer wire, and first and second stent grafts as described above andof appropriate length are chosen based upon the measurements takenduring the angiogram. A first catheter delivery system is advanced overthe stiffer guidewire through the first femoral and iliac arteries ofthe patient to a location beyond (e.g., upstream of) the aneurysm in theaorta. The first stent graft (with flexible guidewire detachablyattached thereto) is advanced with the first catheter delivery system toa location traversing the aneurysm in the aorta. The first catheterdelivery system is operated to deploy the first stent graft and attachedguidewire, and is then withdrawn. Deployment causes the upper tubularbody of the first stent graft to expand within the aorta, and the firstoutlet of the first tubular leg to expand within the first iliac artery.

Next, a guidewire engagement device useful for grasping or manipulatingthe flexible guidewire is inserted through the second incision in thepatient and advanced distally through the second femoral and iliacarteries to the aorta. The engagement device is then used to grasp,pull, or otherwise manipulate the flexible guidewire out of the firstiliac artery and retracted proximally through the second iliac andfemoral arteries. The flexible guidewire is preferably long enough sothat its proximal end can be pulled out through the second incision inthe second femoral artery so that it can be grasped by the surgeon whilea guide catheter is advanced over it as further discussed below.

At this point, the first stent graft is fixed within the aorta with thefirst tubular leg fluidly coupling a healthy section of aorta upstreamof the aneurysm with the first iliac artery, and the second tubular legis fully disposed within the aorta upstream of the second iliac artery.A guide catheter is advanced through the second incision and over theflexible guidewire, which is attached to the first stent graft. Theflexible guidewire guides the guide catheter through the second femoraland iliac arteries, through a portion of the aorta, and into the secondtubular leg of the first stent graft. It will be appreciated that theattachment of the flexible guidewire to the upper tubular body of thefirst stent graft and its extension through the second tubular leg makesit much easier for the surgeon to advance the guide catheter into thesecond tubular leg.

Once the guide catheter is disposed inside the second tubular leg of thefirst stent graft, the guide catheter delivery system is furtheradvanced distally (upstream) to detach the flexible guidewire from thefirst stent graft (e.g., by applying a longitudinal pushing forceagainst the attached distal end of the flexible guidewire). The flexibleguidewire is then pulled proximally through the second tubular leg, theaorta, the second iliac and femoral arteries, and out of the patientthrough the second incision while the guide catheter remains advancedwithin the second tubular leg.

A stiffer guide wire is then introduced into the patient and advanceddistally through the guide catheter to the distal end of the guidecatheter. The guide catheter is then removed from the patient, and asecond catheter delivery system provided with the second stent graft isdistally advanced through the patient over the stiffer guide wire to thesecond tubular leg of the first stent graft. The second stent graft isthen deployed from the second catheter delivery system into engagementwith the second tubular leg of the first stent graft. It will beappreciated that the first and second stent grafts will now definepassageways for bloodflow from the aorta upstream of the aneurysm toboth of the common iliac arteries downstream of the aneurysm whileexcluding the damaged or otherwise unhealthy portion of the aorta. Itwill also be appreciated that this method of advancing and deploying thefirst and second stent grafts through the femoral, iliac, and aorticarteries may be used in other medical applications (e.g., medicalapplications in which other blood vessels include a target vessel andone or more branch vessels), and that bifurcated stent grafts having anattached guidewire may be used in other parts of the body besides theabdominal aorta.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the first stent graft, the second stentgraft, and the flexible guidewire in accordance with the presentinvention.

FIG. 2A is a schematic view of one embodiment of the invention in whichthe flexible guidewire is detachably attached to an upper rim of thefirst stent graft.

FIG. 2B is a schematic view of another embodiment of the invention inwhich the flexible guidewire has a hook which is detachably attached toa protrusion extending from an inner surface of the first stent graft.

FIG. 3A is a schematic view of first and second iliac arteries and firstand second femoral arteries in a patient, as well as an angiogramcatheter.

FIG. 3B is a schematic view of a delivery catheter advanced through thefirst femoral artery, the first iliac artery, and the aorta.

FIG. 4 is an enlarged schematic view of the aorta, iliac arteries, anddelivery catheter of FIG. 3B with a portion of the first stent graftdeployed within a healthy portion of the aorta.

FIG. 5 is a schematic view of the aorta, iliac, and femoral arteries ofFIG. 4 with the first stent graft fully deployed within both the aortaand the first iliac artery, the flexible guidewire extending through thesecond tubular leg of the first stent graft and the first iliac artery,and a guidewire engagement device disposed in the second iliac andsecond femoral arteries.

FIG. 6 is a schematic view of the aorta, iliac and femoral arteries,first stent graft, and flexible guidewire of FIG. 5 with the flexibleguidewire extending through the second tubular leg of the first stentgraft and the second iliac and second femoral arteries.

FIG. 7 is a schematic view of the aorta, iliac and femoral arteries,first stent graft, and flexible guidewire of FIG. 6, as well as a guidecatheter advanced through the second femoral artery and second iliacartery over the flexible guidewire.

FIG. 8 is a schematic view of the aorta, iliac and femoral arteries,first stent graft, flexible guidewire, and guide catheter of FIG. 7 withthe guide catheter advanced beyond the attachment end of the flexibleguidewire and the guidewire detached from the first stent graft.

FIG. 9 is a schematic view of the aorta, iliac and femoral arteries,first stent graft, stiffer guide wire, and second delivery catheter andstent delivery device with a portion of the second stent graft deployedfrom the second delivery catheter and expanded within the second tubularleg of the first stent graft.

FIG. 10 is a schematic view of the aorta, iliac and femoral arteries,and first and second stent grafts of FIG. 9 with the second stent graftfully deployed and extending within the second tubular leg of the firststent graft, the aorta, and the second iliac artery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIG. 1, the invention includes a first stent graft 10, asecond stent graft 12, and a flexible guidewire 14 for use in bloodvessels of a patient. The first stent graft 10 has an upper tubular body16 which defines a hollow inlet 18, and a lower bifurcation 20 whichincludes a first tubular leg 24 defining a first outlet 22 a and asecond tubular leg 26 which is shorter than the first tubular leg 24 anddefines a second outlet 22 b. The first and second tubular legs 24, 26are in fluid communication with the hollow inlet 18. The first stentgraft 10 is preferably made from at least one metal form structure 11,comprising struts 25, in combination with a flexible fabric 13.

The second stent member 12 is also preferably made from at least onemetal form structure 19, comprising struts 27, in combination with aflexible fabric 21, and comprises a hollow elongated member having asingle inlet 28 and a single outlet 30. The inlet 28 of the second stentmember 12 is adapted to be insertable into the hollow second leg 26 ofthe first stent graft 10 inside the aorta of a patient as furtherdiscussed below.

The first and second stent grafts 10, 12 may be made from any materialsknown in the art which are suitable for advancement through the femoral,iliac, and aortic arteries of a patient, and for deployment in the iliacand aortic arteries. For the graft, such materials, for example, may beformed from a twill weave, non-crimped polyester, Gore-Tex®, Dacron® orequivalent biocompatible material. For the stents, materials such assuper-elastic or heat activated nickel-titanium metal alloys may beused, which give them sufficient shape memory and/or bias toautomatically expand them to an expanded configuration in the aortic andiliac arteries of a patient. Alternatively, the stent may comprisepressure expandable structured elements. The first and second stentgrafts 10, 12 are therefore sufficiently collapsible and flexible toallow them to be inserted into a standard delivery catheter for deliveryto and deployment at and adjacent an aneurysm in the aorta of a patientas further discussed below with respect to FIGS. 4-10.

The flexible guidewire 14 extends through the second tubular leg 26 andsecond outlet 22 b of the lower bifurcation 20 of the first stent graft10, and is detachably attached at an attachment end 15 to the firststent graft 10, preferably to an interior surface 17 of the uppertubular body 16. Glue may be used to form the attachment bond betweenthe attachment end 15 and the interior surface 17 of the upper tubularbody 16, and other adhesive materials known in the art may also beutilized, provided that the guidewire 14 is detachable from the uppertubular body 16 via a longitudinal force received at the attachment end15 in vivo during a stent graft procedure, as further discussed belowwith respect to FIG. 8. The flexible guidewire 14 is preferably at least65 cm in length and 0.35 mm or less in diameter.

Turning to FIG. 2A, one embodiment of the apparatus of the invention isshown in which an upper tubular body 116 of a first stent graft 110according to the invention includes an upper rim 132 at one end of thefirst stent graft 110, and a guidewire 114 includes a hook 134 which isdetachably attached to the upper rim 132. The hook 134 may be attachedto the upper rim 132 with glue or other suitable adhesive, or may simplyhook onto the upper rim 132. The hook 134 should be provided with ablunt tip 137 so as to not pierce the first stent member 110 duringadvancement through and deployment of the first stent member 110 in thepatient.

Turning to FIG. 2B, another embodiment of the apparatus of the inventionis shown in which an upper tubular body 216 of a first stent graft 210includes an internal lip, shelf, or other protrusion 235 extending froman interior surface 117, and a guidewire 214 detachably attached to theprotrusion 235 via glue, a hook, or other suitable fastener.Alternatively, the guidewire may be directly attached or tied to a strut225 of the metal form structure stent portion of the stent graft 210 ortied to fabric 221 of the stent graft 210.

As further discussed below, once deployed within the patient with thefirst stent graft 10, the flexible guidewire 14, by virtue of beingattached to the first stent graft 10, is manipulatable by a surgeon fromthe first iliac artery to the second iliac artery in the patient so thatit can function to guide the advancement of a guide catheter through thesecond iliac artery and into the second tubular leg 26 of the firststent graft 10 in order to guide a stiffer guide wire which is distallyadvanced into the second tubular leg of the first stent graft. Asfurther discussed below, the guide catheter is then removed and a secondcatheter delivery system is advanced over the stiffer guide wire throughthe second iliac artery and into the second tubular leg of the firststent graft within the aorta to facilitate delivery and deployment ofthe second stent graft therein.

Prior to introducing the first and second stent grafts 10, 12 andflexible guidewire 14 into the patient, preparations for taking andperforming an angiogram of the aneurysm and the surrounding bloodvessels are as follows. Turning to FIG. 3A, according to well-knowntechniques, the patient is anesthetized with all standard precautions.First and second incisions 40, 42 are made in the patient to exposefirst and second femoral arteries 44, 46. A needle (e.g. 9-11 French—notshown) having a bore is inserted through the first incision 40 into thefirst femoral artery 44. A thin guidewire 43 (e.g., a 0.35 mm Bensonwire) is inserted through the first incision 40 via the bore of theneedle into the first femoral artery 44 and advanced through the firstfemoral artery 44, through the first iliac artery 48 (which is a directcontinuation of the first femoral artery 44), through a portion of theaorta 50, to a location in the approximate vicinity of the aneurysm 52in the aortic wall 53. A sheath (e.g., 6 Fr—not shown) is then connectedat the site of arteriotomy in the first femoral artery 44 and anangiogram catheter 45 (e.g., a 5 Fr. 65 cu/90 cm pig tail catheter) isinserted through the sheath and into the abdominal aorta. An angiogramis then performed and measurements are taken to determine theapproximate distance from, for example, the aneurysm 52 to thebifurcation 56 where the aorta 50 branches into the first and secondiliac arteries 48, 49, or the distance from the aneurysm 52 to each ofthe first and second iliac arteries 48, 49).

After performing the angiogram, the thin guidewire 43 is then proximallyretracted from the patient through the first femoral and iliac arteries44, 48 without retracting the catheter 45, and a stiffer guidewire 47(e.g., a 260 cm/300 cm wire) (FIG. 3B) is advanced through the catheter45 to the distal end of the catheter 45. The catheter 45 is then removedfrom the patient through the first femoral and iliac arteries 44, 48,and first and second stent grafts as described above and of appropriatelength are chosen based upon the measurements taken during theangiogram.

Turning to FIG. 4, a first catheter delivery system 58 (preferably atleast a 20 Fr. delivery system) provided with the first stent graft 10is advanced over the stiffer guidewire 47 through the first femoral andfirst iliac arteries 44, 48 of the patient to a location beyond (e.g.,upstream of) the aneurysm 52 in the aorta 50. The first stent graft 10with flexible guidewire 14 detachably attached thereto is then deployedfrom the first catheter delivery system 58 to the location upstream ofthe aneurysm 52. The first catheter delivery system 58 may utilize anytype of catheter and stent delivery device known in the art which aresuitable for deployment in the abdominal aorta. For example, stentdelivery devices are discussed in U.S. Pat. No. 7,594,926 to Linder,which is herein incorporated by reference in its entirety. As shown,during deployment from the first catheter delivery system 58, the stentgraft 10 moves from a collapsed state within the first catheter deliverysystem 58 to an expanded state outside of the catheter delivery system58 within the aorta 50.

Turning to FIG. 5, the first catheter delivery system has beencompletely removed from the patient, leaving the first stent graft 10and flexible guide wire 14 fully deployed with the hollow inlet 18 ofthe upper tubular body 16 positioned upstream of the aneurysm 52, thefirst tubular leg 24 of the lower bifurcation 20 expanded within boththe aorta 50 and the first iliac artery 48 with the first outlet 22 apositioned inside the first iliac artery 48, and the second tubular leg26 expanded within the aorta 50.

A needle (not shown) is then inserted through the second incision 42into the second femoral artery 46, and a sheath (not shown) is thenconnected at the site of arteriotomy in the second femoral artery 46. Asnare, hook, pig-tail, clasp, or other guidewire engaging instrument 60useful for grasping or manipulating the flexible guidewire 14 isinserted through the second incision 42 (FIG. 3A) via the bore of theneedle through the sheath into the patient, and advanced distallythrough the second femoral and second iliac arteries 46, 49 to the aorta50. As shown in FIG. 5, the flexible guidewire 14 extends at this pointthrough the second tubular leg 26 of the first stent graft 10 toward andthrough the first iliac artery 48 and first femoral artery 44. Theguidewire engaging instrument 60 is then used to snare, grasp, pull, orotherwise manipulate the flexible guidewire 14 out of the first iliacartery 48 and retract it proximally through the second iliac artery 49and second femoral artery 46 by retracting the guidewire engaginginstrument 60 proximally through the second iliac artery 49 and secondfemoral artery 46. The flexible guidewire 14 is preferably long enoughso that its proximal end can be pulled out through the second incision42 in the second femoral artery 46 and grasped by the surgeon while aguide catheter is distally advanced over it as further discussed below.

Turning now to FIG. 6, the first stent graft 10 is fixed within theaorta 50 with the first tubular leg 24 fluidly coupling a healthysection 62 of the aorta 50 upstream of the aneurysm 52 with the firstiliac artery 48, with the second tubular leg 26 fully disposed withinthe aorta 50 upstream of the second iliac artery 49, and with theflexible guidewire 14 still attached to the upper tubular body 16 of thefirst stent graft 10 and now extending through both the second tubularleg 26 and the second iliac artery 49.

Turning to FIG. 7, a guide catheter 51 is advanced through the secondincision 42 over the flexible guidewire 14. The flexible guidewire 14guides the guide catheter 51 through the second femoral and iliacarteries 46, 49, through a portion of the aorta 50, and into the secondtubular leg 26 of the first stent graft 10. It will be appreciated thatthe attachment of the flexible guidewire 14 to the upper tubular body 16of the first stent graft 10 and its extension through the second tubularleg 26 will make it much easier for the surgeon to advance the guidecatheter 51 into the second tubular leg 26 as the surgeon will not needto precisely position the guide catheter 51 in alignment with the secondtubular leg 26 prior to distally advancing the guide catheter 51.Instead, the surgeon can simply advance the guide catheter 51 over theguidewire 14, and the guidewire 14 will guide the distal end of theguide catheter 51 into the second outlet 22 b of the second tubular leg26. Thus, the time for the surgeon to accomplish this critical step isreduced. In addition, it will be appreciated that the orientation of thesecond tubular leg 26 relative to the bifurcation 56 is rendered lessimportant because it is not necessary for the surgeon to blindly guide aguidewire into the second tubular leg 26 prior to advancing the guidecatheter 51.

Turning to FIG. 8, once the guide catheter 51 is disposed inside thesecond tubular leg 26 of the first stent graft 10, the guide catheter 51is further advanced distally (upstream) to detach the attachment end 15of the flexible guidewire 14 from the interior surface 17 of the firststent graft 10 (e.g., by applying a longitudinal pushing force againstthe attachment end 15 of the flexible guidewire 14). As the uppertubular body 16 of the first stent graft 10 is wedged inside of theaorta 50, it is longitudinally fixed thereto, and thus will supply anequal and opposite longitudinal force to the bond between the attachmentend 15 and the interior surface 17, causing sheer stress sufficient tobreak the bond (or to release the otherwise formed mechanical attachmentbetween the flexible guidewire 14 and the first stent graft 10). It willbe appreciated that the bond between the attachment end 15 and the firststent graft 10 should be strong enough to resist separation when theguide catheter 51 is initially placed in the patient and distallyadvanced through the second iliac artery 49 over the guidewire 14, butweak enough to separate when the distal end of the guide catheter 51reaches the attachment end 15 and applies a longitudinal force thereto.If the attachment end 15 is hooked to an upper rim or shelf/protrusionextending from the interior surface 17 of the first stent graft 10 asdiscussed with respect to FIGS. 2A and 2B, then such upper rim, shelf,or protrusion is preferably made from material which will not break offof the interior surface 17 so that such material will not enter thebloodstream.

Once the flexible guidewire 14 is separated from the first stent graft10, it is retracted proximally through the second tubular leg 26, theaorta 50, the second iliac and femoral arteries 49, 46, and out of thepatient through the second incision 42 while the guide catheter 51remains advanced within the second tubular leg 26. At this point, itwill be appreciated that locational access to the second tubular leg 26is provided for any desired use. By way of example, an angiogram may beconducted. Also, a stiffer guide wire 55 (FIG. 9) may then be advancedthrough the guide catheter 51 to the distal end of the guide catheter 51inside the second tubular leg 26, and the guide catheter 51 may beremoved, leaving the stiffer guide wire 55 in place.

Turning to FIG. 9, with the stiffer guide wire 55 in place, a secondcatheter delivery system 64 (preferably at least 20 Fr.) may be providedwith the second stent graft 12 and a stent delivery device 23 and may beintroduced into the patient through the second incision 42 and distallyadvanced over the stiffer guide wire 55, which guides the secondcatheter delivery system 64 through the second femoral and iliacarteries 56, 49 and aorta 50, and into the second tubular leg 26 of thefirst stent graft 10.

The second stent graft 12 can then be deployed from the second catheterdelivery system 64 inside the second tubular leg 26 of the first stentgraft 10 (e.g., the delivery catheter is refracted proximally relativeto the stent delivery device 23, which is held longitudinally fixed,which deploys the second stent graft 12). The stiffer guide wire 55 maybe removed from the patient before or after deployment of the secondstent graft 12. The second catheter delivery system 64 can be operatedto deploy the second stent graft 12 between the hollow second leg 26 andthe second iliac artery 49 such that the second outlet 22 b ispositioned within the second iliac artery 49 as shown in FIG. 10.

It will be appreciated that the first and second stent grafts 10, 12will now define passageways for bloodflow from the aorta 50 upstream ofthe aneurysm 52 to both of the common iliac arteries 48, 49 downstreamof the aneurysm 52 while excluding the damaged or otherwise unhealthyportion (e.g., the aneurysm 52) of the aorta 50. Additional stent graftsmay be applied to one or more blood vessels as needed.

There have been described and illustrated herein several embodiments ofan apparatus and a method of repairing abdominal aortic aneurysms. Whileparticular embodiments of the invention have been described, it is notintended that the invention be limited thereto, as it is intended thatthe invention be as broad in scope as the art will allow and that thespecification be read likewise. Thus, while particular shaped and sizedstent grafts have been disclosed, it will be appreciated that othershapes and sizes may be used as well. While first and second stentgrafts having a metal form structure in combination with a flexiblefabric have been disclosed, it will be appreciated that other materialsmay be used to form the first and second stent grafts. In addition,while particular types of adhesives have been disclosed, it will beunderstood that other adhesives and fasteners can be used. Also, while abifurcated first stent graft and an elongate second stent graft havebeen disclosed, it will be recognized that additional stent grafts canbe attached to the respective ends of the first and second stent grafts,and/or to additional blood vessels as needed. For example, it will beappreciated that extension stent grafts may be added to the upstream endof the first stent graft and to the downstream end of the second stentgraft, and that stent grafts with attached guidewires may be used forother medical applications. While a particular catheter delivery systemfor delivering and deploying a stent graft has been disclosed, it willbe appreciated that other catheter delivery systems for delivering anddeploying stent grafts known in the art may be employed. Furthermore,while a particular method has been disclosed, it will be understood thata number of steps of the method of the invention may be eliminated ormodified as needed, and that the method may be used for bifurcated stentgrafts applicable to other medical procedures in which a catheter needsto be guided into a specific leg of the bifurcated stent. It will alsobe appreciated that while a method for repairing an aneurysm in theaorta of a patient has been disclosed, the method may be modified andutilized to repair an aneurysm in another blood vessel of the patient,such as, for example, an aneurysm in the iliac artery of a patient. Itwill therefore be appreciated by those skilled in the art that yet othermodifications could be made to the provided invention without deviatingfrom its spirit and scope as claimed.

What is claimed is:
 1. An apparatus comprising: a first stent graft; anda second stent graft, wherein, said first stent graft is discrete fromsaid second stent graft, said first stent graft is made from a metalform structure in combination with a flexible fabric, said first stentgraft having an upper tubular body including a first portion of saidmetal form structure and a first portion of said flexible fabric and alower bifurcation, said upper tubular body defining an inlet, said lowerbifurcation including a first tubular leg including a second portion ofsaid metal form structure and a second portion of said flexible fabricand defining a first outlet and a second tubular leg including a thirdportion of said metal form structure and a third portion of saidflexible fabric and defining a second outlet, said second tubular legconfigured to engage said second stent graft, said first and secondoutlets in fluid communication with said inlet of said upper tubularbody, said first tubular leg having a first length from said firstoutlet to a bifurcation end of said first portion of said flexiblefabric, and said second tubular leg having a second length from saidsecond outlet to said bifurcation end of said first portion of saidflexible fabric, said second length being shorter than said firstlength, said first stent graft movable between a first collapsed statefor delivery through blood vessels in a body of a patient and a secondexpanded state for deployment at a target blood vessel with said inletof said upper tubular body positioned upstream of an aneurysm or otherdefect in the target blood vessel, said first outlet positioned in afirst branch vessel downstream of the target vessel, and said secondoutlet positioned at or adjacent the aneurysm or other defect; and aflexible guidewire having a terminal end detachably attached to saidupper tubular body at a location on the upper tubular body that is aboveand upstream of said bifurcation and having another end extendingthrough said second tubular leg, wherein said flexible guidewire isattached to said upper tubular body in a first configuration in whichsaid second tubular leg is not engaged with the second stent graft, andwherein said flexible guidewire is detached from said upper tubular bodyin a second configuration in which said second tubular leg is engagedwith the second stent graft.
 2. An apparatus according to claim 1,wherein: said flexible guidewire is detachably bonded to said uppertubular body.
 3. An apparatus according to claim 1, wherein: saidguidewire includes a hook, and said hook is detachably attached to saidupper tubular body.
 4. An apparatus according to claim 1, wherein: saidupper tubular body has an inner surface which defines said inlet of saidupper tubular body, and said guidewire is detachably attached to saidinner surface.
 5. An apparatus according to claim 1, wherein: said uppertubular body includes a lip, and said guidewire is detachably attachedto said lip.
 6. An apparatus according to claim 1, wherein: saidflexible guidewire is at least 65 cm in length.
 7. An apparatusaccording to claim 1, wherein: said guidewire has a diameter, and saiddiameter is no more than 0.35 mm.
 8. An apparatus according to claim 1,wherein: said second stent graft defines an inlet and an outlet and ismade from a metal form structure in combination with a flexible fabric,said second stent graft is movable between a first collapsed state fordelivery through blood vessels into the body of the patient, and asecond expanded state for coupling to said first stent graft at thetarget blood vessel with said inlet of said second stent graftpositioned inside said second outlet of said second tubular leg of saidfirst stent graft, and said outlet of said second stent graft ispositioned in a second branch vessel downstream of the target vessel. 9.An apparatus according to claim 1, further comprising: a third stentgraft insertable into said first tubular leg of said lower bifurcationof said first stent graft in the first branch vessel.
 10. An apparatuscomprising: a first stent graft; and a second stent graft, wherein, saidfirst stent graft is discrete from said second stent graft, said firststent graft is made from a metal form structure in combination with aflexible fabric, said first stent graft having an upper tubular bodyincluding a first portion of said metal form structure and a firstportion of said flexible fabric and a lower bifurcation, said uppertubular body defining an inlet, said lower bifurcation including a firsttubular leg including a second portion of said metal form structure anda second portion of said flexible fabric and defining a first outlet anda second tubular leg including a third portion of said metal formstructure and a third portion of said flexible fabric and defining asecond outlet, said second tubular leg configured to engage said secondstent graft, said first and second outlets in fluid communication withsaid inlet of said upper tubular body, said first tubular leg having afirst length from said first outlet to a bifurcation end of said firstportion of said flexible fabric, and said second tubular leg having asecond length from said second outlet to said bifurcation end of saidfirst portion of said flexible fabric, said second length being shorterthan said first length, said first stent graft movable between a firstcollapsed state for delivery through blood vessels in a body of apatient and a second expanded state for deployment at a target bloodvessel with said inlet of said upper tubular body positioned upstream ofan aneurysm or other defect in the target blood vessel, said firstoutlet positioned in a first branch vessel downstream of the targetvessel, and said second outlet positioned at or adjacent the aneurysm orother defect; and a flexible guidewire having a terminal end detachablyattached to said upper tubular body at a location on the upper tubularbody that is above and upstream of said bifurcation and having anotherend extending through said second tubular leg, said guidewire having alength and a diameter, said diameter no more than 0.35 mm and saidlength at least 65 cm; and means for detachably attaching an attachmentend of said flexible guidewire to said upper tubular body of said firststent graft, said means for detachably attaching adapted to maintainattachment of said attachment end of said flexible guidewire to saidupper tubular body while said first stent graft is advanced throughblood vessels toward the aneurysm, wherein said flexible guidewire isattached to said upper tubular body in a first configuration in whichsaid second tubular leg is not engaged with the second stent graft, andwherein said flexible guidewire is detached from said upper tubular bodyin a second configuration in which said second tubular leg is engagedwith the second stent graft.
 11. A stent graft according to claim 10,wherein: said means for detachably attaching is adapted to allowdetachment of said flexible guidewire from said upper tubular body uponapplication of a longitudinal force in the distal direction on saidmeans for detachably attaching by a guide catheter.